Table 3.
Cytotoxicity IC50 Values for 2-(2-Pyridyl)Benzazole Ligands and Ru Complexes in the HL60 Cancer Cell Line
| Comp. | Coligand | Y | Dark IC50 [μM] | Lighta IC50 [μM] | PI |
|---|---|---|---|---|---|
| 1 | – | CH | >100 | n.d.b | n.d. |
| 2 | – | NH | >100 | n.d. | n.d. |
| 3 | – | O | >100 | n.d. | n.d. |
| 4 | – | S | >100 | n.d. | n.d. |
| 5 | dmphen | CH | 0.34 (±0.008) | 0.034 (±0.001) | 10 |
| 6 | dmphen | NH | 2.79 (±0.31) | 4.49 (±0.07) | 0.6c |
| 7 | dmphen | O | 4.54 (±1.37) | 3.43 (±0.75) | 1.3 |
| 8 | dmphen | S | 1.55 (±0.41) | 4.55 (±1.73) | 0.3c |
| 9 | bpy | CH | 1.24 (±0.008) | 0.18 (±0.001) | 7.3 |
| 10 | bpy | NH | 44.8 (±0.4) | 0.20 (±0.017) | 224 |
| 11 | bpy | O | 63.5 (±8.3) | 5.18 (±0.047) | 12.2 |
| 12 | bpy | S | 83.3 (±1.2) | 0.94 (±0.09) | 88 |
| Cisplatin | – | – | 3.1 (±0.2) | 3.1 (±0.2) | 1 |
a
Using the Loctite Indigo LED array (light dose of 29.1 J/cm2)
b
n.d. – not determined.
c
The PI values reflect differences in the slopes of the dose response curves, and likely indicate that different cytotoxicity mechanisms are responsible for cell death in the dark vs. light conditions.